Pressure gauge



A. l. FERRIER PRESSURE GAUGE Jan. 15, 1935.

Filed July 17. 1929 2 Sheets-Sheet l l fl/farm y.

Jan. 15, 1935. A. l. FERRIER 1,987,673

' PRESSURE GAUGE Filed July 1'1, 1929 2 Sheets-Sheet 2 Patented Jan. 15, 1935 PRESSURE GAUGE Y Alexander I. Ferrier, Detroit, Mich., assignor, by mesne assignments, to General-Motors Corporation, Detroit, Mich, a corporation of Delaware 1 Application July 17. 192a' Serial No. 373,935

6 Claims.

This invention relates'to pressure gauges, and

especially to that type of pressure gauge embodying or employing a Bourdon tube therein." More particularly the inventionrelates to a calibrating device for connecting the free end of thetube and the pointer or indicator of the gauge.

A major purpose of thepresent invention is to simplify and improve the general construction of devices of this character. v t i A further object of the invention is to provide in a pressure gauge. a lever and link connection between a Bourdon tube and an indicator or pointer so arranged that the effective leverage of the device may be readily varied so that the movement of the indicator overthe dial maybe calibrated to make the dial divisions agree with equal pressure increments.

It is a still further object of the present invention to provide a device of the class set forth which will be simple and convenient of manufacture and assembly; which will be efiicient in operation; which will have aminimum numberof parts therein; and which will be both strong and durable.- Further 'objects nf the invention will be hereinafter more fully set-forth.

The accompanying drawings illustrate several forms of pressure gauge embodying the present invention which will be described in detail to enable others to understand and use the same, but the invention is not considered restricted to the specific constructionshown in the draw-ings and reference is therefore had to the claims for summaries of the essentials of-the invention and of the novel features of construction and of the Figure 1 is a view of a pressure gauge of the class set forth, therear wallthereof beingbroken away to illustrate the interior construction and assembly.

Figure 2 is a sectional view taken on the line 2-2 of Figure 1.

Figure 3 is an enlarged detail plan view of one form of calibrating stem and lever connection constructed in accordance with the present invention.

Figure 4 is a front view of the form of the invention illustrated in Figure 3.

Figure 5 is a detail sectional view taken on the line 55 of Figure 4 illustrating the connection between the stem and the Bourdon tube.

Figure 6 is an enlarged detail plan view of a modified form of calibrating stem and lever connection embodying the present invention.

Figure Us a viewin front elevation of the formof the invention illustrated in Figure 6. Figure 8 is an end view-of the stem illustrating the connection thereof-with the Bourdon tube.

Figure 9 is a plan view illustrating the mounting .of this form of the invention within the gauge casing proper, y 1 1 Figure 10 is a view in end elevation illustrating a slightly further modified form of'the inventionf Figure 11 is a view in front elevation of the form of the invention illustrated in Figure 10.

There has been illustrated inthe drawings, conventionally, the usualtype of pressure gauge including a casing '10, a dial 11 over which travels an indicator ,or. pointer 12; and a glass or glazed, front covering 13 protecting the dial and indi-. cator. .AgBourdon tube 14 is mounted within the casing vandhas an end thereof fitted .to a nipple or "thelike 15 by which the tube is connectedtd a line of pipe or the like containing fluid, the.pres-:- sure-of which is'tobe indicated. 1' l 1 i Obviously .the gauge, and the tube therein and other .associated parts may be. of any desired constructionas is .well known'in the art-and may be of any-size and capacity to meet the particular requirements desired, and while the gauge as .il-- lustrated is especially designed to indicate the" air pressure as-withinpneumatic tires or the like, this showing is merely illustrative. and not in any way limitive. :In, the form of the invention illustrated more particularly in Figures 1 through 50f the ,drawings inclusive, therejiszprovided a calibrating 'de-' vice or. stem comprising a .U-shaped bodyxhaving parallel arms 16 to which are attached by any i suitablemeans such as welding, riveting, brazing or=the like, a pair of stub shafts 17 .byvwhichthe stem is journalled in the casing 10, 'one:of .these shafts 17 projecting through the dial and beingalkm designed to carry the indicator orpointer thereon. Extending from the middle portion of the body is a bendable arm or the like 18 having the extremity 19 thereof bent to extend between the arms of the body and also twisted to lie in a plane parallel to the said arms. A link 20 is pivotally connected to this arm end 19, the opposed extremity of the link being adapted for pivotal connection or engagement with the free extremity of the Bourdon tube 14. It will be noted that the pivotal connection 21 between the link 20 and the arm 18 is offset with respect to the center of the stub shafts 1'7 by which the member 16 is mounted or journalled; by properly bending the said arm 18 the distance from the axis of the shafts 17 to the pivotal center 21 may be varied so that the ratio of movement between the end of the Bourdon tube and indicator may be varied to properly calibrate the gauge. In the form of the invention illustrated in Figures 6 to 9 inclusive, of the drawings, the calibrating stem is substantially identical with the first described:rorng the difierences beingim the eonstrueuonrandshapes: the: pa'rtsfitfiisi fcini of the invention illustrating the body portion stamped from sheet metal. In this modification the stem comprises a U-shaped stampinggiO, the base of which is of uniform width throughoutas best shown in Figure 7. The armsg-ld', however,"

and carry a pair of stub shafitssl'l r' atv thefeupper extremity. Extending from the. middle portion of the base and integral therewithis"a*bendable" arm 18 having the extremity 19' thereof bentto extend between the arms of the stem and also twisted to lie in a nland-parallel to'the arms; In

this form, a u 'shaped bracing memberfl isse the stem stamping-that maybe used-in the above assembly; The stamping" 40- i has a'base" that'- is narrower than iniFigure- :'7;' and'-has a. projecting ;portion 43 which i is in't'egral with the beridable amse' 'carrying :th-es'end -lQ'I for connection to the 'lirilmos The arms-16R are narrower, of course, but'stillitriangular and carry similar stub shafts 17" Thisicalibratingiestem 'may, of: course; be

It will be notedthatthei calibrationi of anion theeherieirr(illustrated formsmfnthe invention is particularly Zsimplei an'di: convenient," comprising 4 1::mei'ely1the mroper adjustment'ofi the center of the piyotalticonnectiomof thef'link' i2o with the body propen withrespbts toi'th centerof'thestubshafts purposes specified. I

It is ebviousithat many minor changes mayibe madeiin ith' iforinfand' constructioii of thefii'nve'n tienr withbut departing tromi -the:material1princi= tot confine Y the invention to: any one' or -more of the-i specific-'1 forms illustrated, but to'i include 'all' r such and othe'i' terms of devices of the class de-" are triangular in shape, tapering fromathe-base;f-

usd r'interchang'eably 111* the-iisuppoi ting struc justdtca position where its axis is substantially in 'alignmentwithxtheiaxis of said stub shafts, and a linlcconnectingr said pivot to said Bourdon 15 tube 1 2. In a pres sure gauge, a casing having a rear waillari'd 'a"dial"supp8rted therein in spaced re- ,lationfito 'the rear wall, a calibrating stem body an' adjiis tabl arm carriedbfsai may; saiiiarni being bendable to adjusbtIi g g a 'poiiitr" se H 4 carrieamwt e sam body; a n connecting-the bylwhioh thessaid bodydsijournalled: 'I'herehas thus been providedzfseveralforrhs cf'a particularly magefllcient devscetoffitheiclasssdescribed and-tor the aim the free endofthe Bourdonlube ts/hereby eat of? the" arm win-wary the iyetar o the arm wan-respect td tl'i' center or. ;shaits thfis to calibfatcfthe dvicel"' r 16; IrTeI-gailfifb, Beware-tube an 'substam" many u siiaea esl-ibr'atifig s'tfii may mouatea i'rr Lang-a ustabie bagablerm carried-by mesaia o'dyia paifor'dpmitayexjt stair shafts rigid with the legs of the body-for journa ling said body in the gauge, a pciii'teifcar r'iedb y 

